Process of utilizing petroleum hydrocarbons



Aug 6, 1929 A. P. BJERREGAARD PROCESS OF UTILIZING PETROLEUM HYDROCARBONS Filed May 3, 1924 ONDE/V555( CUM/DRESSOR .0 #m 6 4 E: CE R N 7. W d 6 M ma W am J m a w w R m E m w m l 'Urn w @2M HW momm www Patented Aug. 6, -1929.

` UNITED STATES PATENT OFFICE.

AUGUST P.- BJERREGAABD, OF OKMULGEE. OKLAHOMA, ASSIGNOB TO- DOHEBTY BE- SEARCH COMPANY, F NEW YORK, N. Y., A CORPORATION OF DELAWARE.

PROCESS OF UTILIZING PETROLEUM HYDROOABBONS.

Application led Kay 3, 1924. Serial N0. 710,738.

This invention relates to the art 'of cracking petroleum and has as its principal object the provision of a process whereby petroleum hydrocarbons may be readily cracked with the production of a high yield of salable products.

Further objects and advantages of the present invention will appear from the following description thereof taken in connection with the accompanying drawing in which The figure is an elevation diagrammati4 cally illustrating an apparatus in which the petroleum cracking process embodying the preferred form of the invention may be carried out.

It has been known to vaporize petroleum hydrocarbons and to crack vapors so produced by superheating them at substantially atmospheric pressure. This process has a number of seeming advantages over the process of cracking petroleum under super-atmospheric pressure as now commonly practised. However, the atmospheric pressure cracking process has not come into favor owing in a great measure to its low yield of salable products. It has always been found that the percentage of fixed gas has been relatively high and that the yield of light hydrocarbons suitable for gasoline has been relatively low.

According to the present invention the percentage yield of gasoline material is not as high as that from several of the well known pressure cracking processes, but some of the gasoline obtained is of particularly high grade, in that, among other favorable characteristics, some of the gasoline from the present process possessesfmarked anti-knock properties; or, in other words, it does not cause knocking of the engine on ordinary overloads and it may be used satisfactorily in engines having much higher compression ratios than the 4 to 1 or the 4, 5 to 1 ratios now almost universally used in this country.` This anti-knock characteristic is much sought after at present, even to the extent of manufacturing special chemicals to mix with the gasoline. Furthermore, the process is so carried on that a high percentage of valuable chemical products and gas is obtained simultaneously and in conjunction with gasoline.

In the apparatus illustrated in the drawing raw material is introduced into the system through pipe 10, which leads to the suction side of pump 12 by which the oil is forced vheavy ends or residues may segregate from the lighter hydrocarbon liquids. Vapors pass out of the upper portion of chamber '20 through pipe 22 to a superheating coil 24 within which the vapors are heated to cracking temperature and pass thence through pipe 26 to the lower portion of a dephlegmator 28.

Dephlegmator 28 acts in the usual manner to throw back hydrocarbons having undesirably high boiling points for treatment in subsequent steps of the process and is preferably provided with a cooling coil 30 in its upper portlon to-increase the space eiciency of the dephlegmator. Liquids condensed out of the vapors by dephlegmator 28 pass 'downwardly through pipe 32 to the upper portion of liquid separator 20a where they mingle with the lighter portion of the liquids coming from separating chamber 20 and the mixture of liquids thus formed passes out of the liquid separator 2O@l through pipe 34 which connects to pipe 10 on the inlet side of the pump 12 so that the non-vaporized material which is suitable for this purpose is passed back to the heating coil 16. Heavy ends or residues which it is desired to discharge from the system pass out from the lower end of liquid separator 2Oa through valved pipe 36.

Vapors from dephlegmator 28 pass out of the top of the dephlegmator through pipe 38 to condenser 40 in which a considerable percentage of the vapors is condensed to form a benzine passing out of the bottom of the condenser 40 through pipe 42 to storage or to a rerun still as desired. Vapors not condensed in condenser 40 leave the lower portion of this condenser through pipe 44.

Prior to this point the process has been carri ed on substantially at atmospheric pressure. The vapors pass through pipe 44 to a compressor 46. The compressed gases from compressor 46 pass through pipe 48 to the upper part of a cooler 50. A certain amount of condensate forms in cooler 50 and is drawn off from the bottom of the cooler through pipe 52. The condensate drawn oil through Cil pipe 52 may, if desired, be treated With cooled sulfuric acid or other suitable esterifying agent to recover olelines contained therein in the form of est-ers. 'lhis condensate may be added to the benzine Ytrom the condenser 40 to be redistilled to recover gasoline.` The majority ot the vapors entering cooler 50 pass through pipe 54 leaving the cooler 5() near its lower end and discharging into the lower end ol' absorber 5G. 'lhe absorber 5G is preferably cooled by refrigerated brine or equivalent means and concentrated sulfuric acid is introduced into the upper end ot this absorber through a trap 58, the acid passing down through absorber 56 countercurrent to the hydrocarbons entering the absorber through pipe 54. 'lhe temperature at which the absorber 56 is operated is important in that by the temperature control the condensation of gasoline may be controlled and the esteritication of the unsaturated hydrocarbonsl in the vapors and gasoline may be controlled. When using concentrated sulfuric acid as the absorbing agent it is preferred to maintain tcn'iperaturesat the bottom ofthe absorber where the vapors enter at about 20o C. to --10O C., depending upon the character of the vapors or the raw stock from which the vapors are produced. Also, the temperatures at the top of the absorber should not rise above 40 C. and are preferably of 30o to 10o C. In the absorber 5G, the gases from pipe 54, consisting largely ol oletines of a carbon content ranging from C2 to C, are brought into intimate Contact With the sulfuric acid. The olelines and acids react in the absorber 56 forming a mixture of dialkyl and acid alkyl sulfates With some sulfuric acid and polymerized oletines, all of which passl out from the bottom of absorber 56 through ialved pipe 60. A substantial amountl o'l gasoline is condensed from the gases in the absorber 5U due to 10W temperature cooling of the brine and the compression of the gases. This gasoline lioats to the top of the acid liquor in the absorber and is drawn oil' through the trapped pipe 62 near the top of the absorber. Unabsorbed gas passes out of the top of the absorber 56 through pipe 64 and may be burnt or otherwise disposed of. The alkyl sulfates recovered are preferably diluted with water and dilute sulfuric acid to hydrolize the sulfatos, this hydrolyzing action preferably being carried on immediately after the acid alkyl sulfatos are removed from the absorber 56. A portion of the hydrolysis takes place when the Water and acid are added to the alkyl sulfatos, but the complete hydrolysis is carried on by distilling the acid liquor. Before the distillation is started any benzine or gasoline or unsaturated hydrocarbon liquids and polymerized unsaturated hydrocarbon liquids are removed from the hydrolysis by means ot gravity separation because the saturated and unsaturated hydrocarbon compounds are lighter than the acid liquor and rise to the surface. When the hydrolyzed alkyl sulfatos have been distilled alcohols corresponding to the various alkyl compounds which are absorbed by the acid are recovered in the condenser as a mixture of alcohols. lhese alcohols may then be separated by distillation and rectification.

'l`he process otl cracking hydrocarbons outlined above is essentially a vapor phase cracking which is carried on at atmospheric pressurc. lhc recovery ot' the gasoline, however, and other chemical products cannot be advantageously carried on at atmospheric pressure and therefore al'ter the main part ofthe gasoline stock has been recovered from the cracked vapors, the remaining vapors are treated under pressure in order to recover a large proportion of the gasoline and to recover the chemical products occurring in the gas along with the gasoline. If an attempt was made to recover the gasoline by compression and cooling, the product recovery would be very unstable. However, by treating the compressed vapors under cooled conditions 'with a cold absorbing acid, the gasoline is recovered as stable gasoline having very valuable properties l'or use in explosive engines. ln particular. as above mentioned, this gasoline has marked anti-knock properties. This is true to such an extent that blended gasoliues containing considerably less than 1/2 ol the kind ot gasoline now under consideration are salable at the present time as antiknock gasolines. The portion of the gasoline recovered in the acid absorber has been freed of the lighter hydrocarbons by the esterlication with acid and only the stable hydrocarbons remain in the gasoline. 0n the other hand, the unsaturated hydrocarbons such as ethylene, propylene, butylene, amylene and liercy'lenc` which are absorbed from the gaseous and liquid unsaturated hydrocarbons passing through the absorber, are products from which valuable chemical compounds may be made. Furthermore, the presence of liquid hydrocarbons in the absorber in the presence of acid assists in the absorption of the lighter unsaturated hydrocarbons in the vapors and liquids, so a high percentage ot conversion may be effected without the polvmerization of oletines.

The process of cracking oil outlined above is particularly adapted for a refinery in that substantially any type of oil may be used as the raw cracking stock. Most pressure cracking processes are limited to the use of gas oil, but in vieny ofthe fact that all cracking in the present process takes place in tht` vapor phase, substantially any form of petroleum distillery slop. heavy or light oils may be used as raw material from which the gasoline and chemical products may be made.

The gas recovered in the process has a comlll) paratively high heat value, and therefore is Well adapted for industrial heating purposes. The alkyl sulfates are preferabl treated in known manner as above describe in detail to obtain alcohol therefrom and the gasoline from absorber 56 is run to storage. This gasoline is of high degree on the Beaum scale and needs little treatment to it it for consumption.

Having thus described my invention, I claim:

1. A process of treating petroleum hydrocarbons com )rising vaporizing said hydrocarbons, cracking said vapors at substantially atmospheric pressure, condensing out benzine from said vapors, and esterfying oleiines formed in the gases by said cracking.

2. A process of treating petroleum hydrocarbons comprising vaporizing said hydrocarbons, cracking said vapors at substantially atmospheric pressure, condensing out benzine from said cracked vapors, contacting the remaining vapors with mineral acid to form alkyl esters, and separating said esters from uncombined hydrocarbon material.

3. A process of treating petroleum hydrocarbons comprising vaporizing said hydrocarbons. cracking said vapors at substantially atmosphericl pressure, condensing out benzine from said cracked vapors, contacting the remaining vapors with acid to form alkyl esters and gasoline, and separating said esters from said gasoline.

4. A process of treating petroleum hydrocarbons comprising vaporizing said hydrocarbons, cracking said vapors at substantially atmospheric pressure, condensing out benzine from said cracked vapors, compressing the remaining vapors and cooling them to separate out a second condensate, contacting the comy pressed vapors with acid to form alkyl esters,

and separating said esters from uncombined hydrocarbon material.

5. A process of treating petroleum hydrobons comprising vaporizing said hydrocarbons, cracking said vapors at substantially atmospheric pressure, condensing out benzine from said cracked vapors, compressing and cooling the remaining vapors to separate out a second condensate, contacting said compressed vapors With cooled acid to form gasoline andalkyl esters, and separating said esters Jfrom said gasoline.

6. A process of treating petroleum hydrocarbons comprising heating said hydrocarbons to vaporize a portion thereof, separating the vapors from the liquid hydrocarbons, heating said vapors to a cracking temperature at substantially atmospheric pressure, dephlegmating said vapors, condensing out benzine from said vapors, compressing the remaining vapors, contacting the compressed vapors with acid to form alkyl esters, and seplarating said esters from uncombined materia 7. A process of Atreating petroleum hydrocarbons comprising heatmg said hydrocarbons to vaporize a portion thereof, separating the vapors from the unvaporized liquid, heating said vapors to cracking temperature at substantially atmospheric pressure, dephlegmating said vapors, condensing out benzine from said vapors, compressing the remaining vapors, contacting said compressed vapors with acid to form alkyl esters and gasoline, and separating said esters from said gasoline.

8. A process of treating petroleum hydrocarbons comprising vaporizing the hydrocarbons, superheating the hydrocarbon vapors while under atmospheric pressure to a cracking temperature, condensing benzine from the cracked vapors, compressing and cooling the remaining vapors to liquefy hydrocarbon material therein, and scrubbing the liquefied and gaeous compressed hydrocarbons with cooled sulfuric acid to esterify unsaturated hydrocarbons therein and separating the esters from uncombined hydrocarbon material.

9. A process of treating petroleum hydrocarbons comprising vaporizing hydrocarbons, superheating the vapors at substantially atmospheric pressure to a cracking temperature, condensing a benzine having a high gasoline content from the cracked vapors, then compressing the remaining vapors and passing the compressed vapors through an absorber counter-current to an acid menstruum passing through the absorber and maintaining the temperature in the absorber below 30 C. f

10. A process of treating petroleum hydrocarbons comprising heating said hydrocarbons to vaporize a portion thereof, separating the vapors from the liquid hydrocarbons, heating said vapors to a cracking temperature at substantially atmospheric pressure, condensing benzine from the cracked vapors, compressing the remaining vapors and cooling the compressedvapors to liquefy hydrocarbon material therein, and scrubbing the compressed hydrocarbons with cooled sulfuric acid to esterify unsaturated hydrocarbons therein, and separating the esters from uncombined h'ydrocarbon material.

11. A process of treating petroleum hydrocarbons comprising heating said hydrocarbons to vaporize a portion thereof, separating the vapors from the liquid hydrocarbons, heating said vapors to a cracking tempera- Ature at substantially atmospheric pressure,

dephlegmating said cracked vapors, condensing out benzine from the cracked vapors, compressing the remaining cracked vapors and cooling the compressed vapors to liquefy certain hydrocarbon material therein, removing said liqueiied hydrocarbon from the compressed vapors, scrubbing liquefied and gaseous compressed hydrocarbons with cooled sulfuric acid to esterify unsaturated hydrocarbons therein with simultaneous production of anti-knock gasoline, and separating the esters from uncombined hydr farben matcrial. I

12. As an article of manufacture a motor gasoline formed by contacting cooled sulfuric acid with petroleum hydrocarbon vapors which have been cracked in the vapor phase and at substantially atmospheric pressure, and having anti-knock properties.

13. The method of making anti-knock gasoline and alkyl esters comprising contacting cooled sulphuric acid with petroleum hydrocarbon vapors which have been cracked inthe vapor phase and substantially at atmospheric pressure.

14. A liquid motor fuel having antiknock properties, comprising a gasoline-like liquid produced by contacting petroleum vapors resulting from cracking petroleum oil in vapor phase at substantially atmospheric pressure with cold sul huric acid maintained under a super-atmosp eric pressure.

15. The method of making a gasoline motor fuel which comprises cracking hydrocarbon oil in vapor phase, increasing the pressure on the resulting cracked vapors and simultaneously cooling and contacting the cracked vapors With sulfuric acid While maintaining said increased pressure.

In testimony whereof I aflix my signature.

AUGUST. P. BJERREGAARD. 

